1. Field of the Invention
The present invention relates to a seat sliding device and in particular to a seat sliding device for use in a motor vehicle.
2. Description of the Related Art
In general, a conventional seat sliding device, as disclosed in Japanese Patent Laid-open Publication No. 62-238136, includes a pair of laterally spaced lower rails both of which are secured to a floor of a vehicle body and a pair of upper rails slidably mounted on the corresponding lower rails. During vehicle collision, a large upward force is applied to the upper rail. In order to prevent separation of each upper rail from the lower rail upon application of such a force, a bent portion is formed on each rail. The bent portions of opposing upper and lower rails are interlocked with each other, thereby preventing separation of the upper rail from the lower rail.
However, if the opposing portions of the upper and lower rail forming the interlocking portion have an insufficient area, the interlocking function may still fail when an unexpected large force is applied to the upper rail, thereby separating the upper rail from the lower rail.
It is an object of the present invention to provide a seat sliding device without the aforementioned drawback.
It is another object of the present invention to provide a seat sliding device in which an interlocking portion of sufficient area can be provided between an upper rail and a lower rail, thereby performing an effective interlocking operation.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
In order to accomplish the above objects, a seat sliding device is provided including an upper rail movable along a lower rail, the upper rail being interlocked with the lower rail upon upward movement of the upper rail, the seat sliding device including an upwardly inclined portion provided with the upper rail, and a downwardly inclined portion provided with the lower rail disposed t  to be interlocked with the upwardly inclined portion upon upward movement of the upper rail.